一种单自由度平面多关节机械手臂的设计与研究

Design and research of single degree of freedom planar multiple joints mechanical arm

针对工业中片状材料自动化传输的应用需求和垂直方向占用空间小的要求,设计了一种成本低、工作空间大和占用空间小的单自由度多关节机械手臂。该机械臂是一种3关节3连杆式机械结构,采用减速机和二级同步带进行传动。利用多坐标系分析方法和角速度叠加原理求出了任意臂长、任意同步带传动比下的末端连杆位姿方程,求出了末端连杆做直线运动的臂长、传动比条件并进行了实验验证。利用拉格朗日方程求出了其动力学方程,并用ADAMS软件仿真验证了其正确性,求出了其在任意位形下的等效转动惯量。搭建了PID闭环控制系统,在一种梯形路径规划下对闭环控制下的驱动力矩进行了仿真研究。研究结果表明,末端连杆直线运动条件和动力学方程推导正确,在示例的路径规划下其驱动力矩要大于25 Nm,为选择驱动力矩元件提供了一种方法和参考。

Aiming at the automatic transmission requirement of sheet material in industry applications and the requirement of small space in vertical direction,a kind of single degree of freedom multiple joints mechanical arm was designed,which has low cost,large workspace and small occupied space. A kind of mechanical structure with 3 joints and 3 links was designed,the reducer and two synchronous belts for drive were used. Using the multiple coordinate system and the superposition principle of angular velocity,the kinematics of the end-link of the arm with arbitrary arm length and arbitrary transmission ratio of the belt was obtained,and the conditions of the linear movement of last link was obtained and verified by the experiment. The dynamical equation was obtained by Using Lagrange equation and it was verified by using ADAMS software,and the moment of inertia under any position was also obtained. A closed loop PID control system was set up,and under a trapezoidal path planning the driving torque in closed-loop control system was simulated and researched. The results indicate that the conditions of the linear movement of the last link and the dynamical equation are correct,and the driving torque under the sample path planning may be greater than 25 Nm,and it provides a way and reference for the select of the driving component.